The butterfly spring connector is a component widely used in various electrical connectors or signal connectors.
A conventional butterfly spring connector typically includes a housing and a butterfly spring. A butterfly spring generally includes an upper piece and a lower piece in connection with the upper piece to form an acute angle. The Butterfly spring is installed inside the housing in any applicable manner, such that the lower piece is fixed to one side wall of the housing, while the free end of the upper piece abuts against the opposite side wall of the frame, or very close to the opposite side wall of the housing. Wire or cable is inserted from the side where connection of the upper piece and lower piece locates, entering into the space between the free end of the upper piece and the housing, whereby the wire or cable is firmly clamped by the upper piece and the opposite side wall of the frame body, due to the spring force of the butterfly spring. The butterfly spring and the housing, or at least the opposite side wall of the housing, is made of electrically conductive material. Therefore, when inserted the wire or cable is in electrical contact with the butterfly springs and/or the opposite side wall of the housing.
The housing is usually coupled to another connector pin or terminal, so to form connections with another terminal, wire or cable. The housing can also be electrically connected to an electrical or electronic circuit directly, in order to provide electrical power or electronic signal to the electrical or electronic circuit or circuits. When removing the wire or cable from the space between the upper piece and the housing, the usual way is to further compress the upper and lower pieces, to release the clamping force applied to the wire or cable by the upper piece. The easiest way to compress the butterfly is to insert, for example, a screwdrivers or a flat object into the space between the upper piece and the housing, while in most butterfly connector products a tongue stopper is moveably or pivotally provided to abut the upper piece, whereby the butterfly spring may be compressed by applying a force to the tongue stopper from external.
In order to adjust the clamping force and stability of the butterfly spring and to simplify the production of the butterfly connector, the industry has developed certain solutions to improve the butterfly spring connector. Most of the solutions provide improvements to the shape, length of the butterfly, its connections with the housing and the shape of the housing.
U.S. Patent Publication US 2011/0312228 (U.S. Pat. No. 8,485,841) discloses a butterfly spring for butterfly spring connector. The butterfly spring has an upper piece, a lower piece and a lateral piece. A tongue stopper is extended from a lateral side of the lateral piece, to engage in a corresponding hole provided at bottom of the housing. The housing provides a symmetric geometry, whereby two insert pins extend from opposite sides of the lower edge and a support is provided at the upper edge and the lower edge, respectively. Two openings are provided at the base portion of the two insert pins. When the butterfly spring is installed inside the housing, with the tongue stopper inserted into one of the openings, the two supports support the butterfly spring. The butterfly connector is in a two-piece design. Therefore, both its production and assembly are difficult.
U.S. Patent Publication US 2011/0207361 discloses a butterfly spring connector. Its housing forms a bottomless U shape frame. At the lower side of the U shape two connector pins extend outward to form a connector clip. Its butterfly spring has an upper piece and a lower piece. The lower piece is affixed and in contact with a side wall of the housing by a plastic frame, so to form electrical connection. The invention further uses the plastic frame to define the butterfly spring. The butterfly spring and the housing have a simple shape, while the connector is complicated in its structure. Manufacture and assembly for this butterfly spring connector are both costly.
U.S. Patent Publication US 2012/0108099 (U.S. Pat. No. 8,579,651) discloses a butterfly spring connector made from a one-piece blank. The butterfly spring has an upper piece, a lower piece and a lateral piece. The lateral piece is extended from a side wall of the housing. The free end of the upper piece forms contact with a central portion of the side wall. Two connector pins extend from the bottom side of the housing to form a connector clip. Wire or cable is inserted between the upper piece and its corresponding side wall. The butterfly spring connector provides a one-piece design, while its clamping force tends to weaken due to elastic fatigue, because the lateral piece extends directly from the side wall. According to its embodiments, to enhance its clamping force, a two-piece design is preferred.
U.S. Patent Publication US 2013/0189861 discloses a butterfly spring connector. The butterfly spring has an upper piece and a lower piece. A lateral piece is formed by a side wall of the housing. The free end of the upper piece abuts against a corresponding side wall of the housing. This side wall includes a plate made of another conductive material, engaged between the upper side and the bottom side of the housing. The butterfly spring connector provides excellent clamping force, while it is difficult to remove the wire or cable from the connector. In addition, its housing has a complex structure, which is difficult to fabricate.
U.S. Patent Publication US 2012/0295495 discloses a butterfly spring connector. The butterfly spring has an upper piece and a lower piece. A lateral piece is formed by a side wall of the housing. The free end of the upper piece abuts against a corresponding side wall of the housing. This side wall is formed by bending and extending the top side and bottom side of the housing. A connector piece is inserted between the upper piece and its corresponding side wall. Two connector pins extend from the connector piece to form a connector clip. The butterfly spring connector provides excellent clamping force, while it is difficult to remove the wire or cable from the connector. In addition, its housing and butterfly spring have a complex structure, which leads to waste of material in fabrication.
From the above description of the known arts, it is appreciated that developments in the design of butterfly spring connector are aimed at a butterfly spring connector that can be produced from a one-piece blank. The butterfly spring connector does not only provide a fine and stable clamping force but also allow a wire or cable be easily removed. Preferably, the butterfly spring connector further allows adjustments in its clamping force in accordance with needs in its applications. In addition, the butterfly spring connectors must be easy to fabricate, able to save materials and fabrication and assembly costs.